Nigeria’s military thwarted suicide attacks Tuesday by two women from the Boko Haram extremist group.

Soldiers shot and killed them before they were able to detonate their explosives in the vicinity of displaced people who had fled their homes because of fighting, an army spokesman, Sani Kukasheka Usman, said in a statement.

Some of the bombers' explosives detonated after they had been shot.

Two civilians were injured in the incident that took place on the outskirts of Monguno town in northeast Nigeria, where Boko Haram is active.

A third suicide attacker blew herself up elsewhere and no one was harmed, the statement said.

US warns of possible attacks

Meanwhile, the United States warned Tuesday of possible attacks against expatriates and foreign visitors in Nigeria's biggest city, Lagos, during the Eid-al-Fitr holidays on July 5 and 6, the end of the Muslim holy month of Ramadan.

“Groups associated with terrorist activity might be planning attacks against hotels in Lagos frequented by international visitors, including those located on waterfronts," a statement on the U.S. Mission in Nigeria website said.

The warning did not mention a specific group but urged U.S. citizens to review their personal security plans, remain aware of their surroundings, including local events, and monitor local news stations for updates.